Letters pages in print newspapers often stand as models of polite and enlightened debate. Readers might avow the wisdom of a columnist or explain where a writer has missed a trick.

Correspondence can examine the finer points of policy or philosophy, with cogent discussions occasionally running over several days, as Mr Smith from Chichester, West Sussex, and Ms Jones from St Davids in Pembrokeshire vie to have the final word.

All of this relies on interesting and knowledgeable letter-writers. But a decent letters page owes much to good editing.

Online, the picture is rather different. There is no space restriction for a start: anybody wishing to see their comment in black and white only has to register an account and get typing.

It’s all jolly democratic and there are good points aplenty being made. But without any editing – moderation is reactive, not proactive – trolls not only get their two penn’orth, they can occasionally dominate. Noise sometimes replaces sense.

It is frequently said that people read whichever newspaper is most likely to take a stance which conforms to their own existing political or ethical preconceptions. That hypothesis works less obviously in relation to online news sites.

On the contrary, there appear to be plenty of people who – to judge from the comments they leave – deliberately read material they deride, albeit that the outcome is the same: they conclude their world view is right and the author of the piece they have pulled to pieces is wrong. It is reinforcement by disparagement, rather than by corroboration.

I was intrigued by some of the responses on The Independent’s website and via Twitter to a piece I wrote last week in the aftermath of the murders of two journalists in Virginia. I had explained why we decided not to show images of the victims, who were killed live on air, from the point at which the shooting began. Most readers who expressed a view seemed to think it was the right choice.

A few disagreed vehemently. One kindly tweeted me the full footage of the killings. Another generously referred to me as “his Saintness William Gore”, before going on to confirm that this was not a compliment by calling me a “preening hypocrite”. I’m certainly easily charmed.

Among the more subtle comments, however, was an interesting point. I had suggested that a reason for not showing the more graphic material was to protect grieving relatives: a reader argued that with the tragedy having taken place in America, we had acted pointlessly to avoid upsetting people who would never read the paper.

Our code of conduct requires that we show sensitivity at times of tragedy. That seems to me simply a matter of general decency. But there are the specific feelings of relatives to consider too and it is true to say that we might ponder on the likelihood of people in faraway places seeing what we have published before we decide what content to show.

In the case of America, The Independent has a sizable online readership so the need to consider the sensibilities of the Parker and Ward families may be more than hypothetical. But in any event, that was only one of several considerations at play.

We also had to think about whether we would be affirming the intentions of the killer if we had shown more detail; and whether there was an overwhelming imperative to show pictures which would undoubtedly have upset a good many, even those with no connection to the dead.

Will Gore is deputy managing editor of The Independent, Independent on Sunday, i and the Evening Standard